• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.4
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• pp.301-313
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• 2015

The rock cavern storage for spent fuel has been assessed to apply in Korea with reviewing the state of the art of the technologies for surface storage and rock cavern storage of spent fuel. The technical feasibility and economic aspects of the rock cavern storage of spent fuel were also analyzed. A considerable area of flat land isolated from the exterior are needed to meet the requirement for the site of the surface storage facilities. It may, however, not be easy to secure such areas in the mountainous region of Korea. Instead, the spent fuel storage facilities constructed in the rock cavern moderate their demands for the suitable site. As a result, the rock cavern storage is a promising alternative for the storage of spent fuel in the aspect of natural and social environments. The rock cavern storage of spent fuel has several advantages compared with the surface storage, and there is no significant difference on the viewpoint of economy between the two alternatives. In addition, no great technical difficulties are present to apply the rock cavern storage technologies to the storage of domestic spent fuel.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.411-422
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• 2016

Recently, because the wet pool storage facilities of NPPs in Korea has become saturated, there has been much active R&D on an interim dry storage system using a transportation and storage cask. Generally, the shielding evaluation for the design of a spent fuel transportation and storage cask is performed by the design basis fuel, which selects the most conservative fuel among the fuels to be loaded into the cask. However, the loading of actual spent fuel into the transportation metal cask is not limited to the design basis fuel used in the shielding evaluation; the loading feasibility of actual spent fuel is determined by the shielding evaluation that considers the characteristics of the initial enrichment, the maximum burnup and the minimum cooling period. This study describes a shielding analysis method for determining the minimum cooling period of spent fuel that meets the domestic transportation standard of the dual purpose metal cask. In particular, the spent fuel of 3.0~4.5wt% initial enrichment, which has a large amount of release, was evaluated by segmented shielding calculations for efficient improvement of the results. The shielding evaluation revealed that about 81% of generated spent fuel from the domestic nuclear power plants until 2008 could be transported by the dual purpose metal cask. The results of this study will be helpful in establishing a technical basis for developing operating procedures for transportation of the dual purpose metal cask.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.293-300
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• 2016

Purpose: The purpose of this study is finding proper bonding agents to be used when adding bis-acryl composite provisional materials. Materials and Methods: Three bonding agents with different chemical compositions were included in this study. Forty disk shaped specimens of bis-acryl composite provisional material were prepared and divided into 4 groups according to the bonding agents. Control group didn't have bonding agent. Through the Teflon mould with 4.0 mm diameter hole with 4.0 mm thickness the same bis-acryl composite provisional material was added on the disks after the surface of each specimen was treated with designated bonding agent according to the manufacturer's instructions. Shear bond test was performed and the fractured surfaces were inspected with a microscope. One-way analysis of variance was conducted and the result was further analysed with Turkey post hoc test at the significance level of 0.05. Results: The highest strength was acquired from the specimens bonded with chemical cure system and it was statistically significant (P < 0.05). This group showed 100% cohesive failures. The lowest bonding strength was recorded from the specimens used conventional light cure bonding agent, and this group's result was similar with the control group. The group used a light cure bonding agent claiming improved compatibility revealed significantly higher bond strength to the traditional light cure bonding agent group in a statistically significant way (P = 0.043). Conclusion: According to the bonding agent used the shear bond strength was significantly affected. Therefore the choice of proper bonding agent is important when hiring a bonding agent to add bis-acryl composite provisional materials.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.3
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• pp.257-264
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• 2011

On April 20, 2010, semi-submersible offshore drilling unit Deepwater Horizon was exploded and sank, and 4.9 million barrels(about 778 thousand tons) of crude oil was spilled into the Gulf of Mexico. As more than one year has been passed since the incident, a lot of investigation reports and lessons learned have been made public and also a lot more will be released soon. This paper studies the final report of the National Commission on "the BP Deepwater Horizon Oil Spill and Offshore Drilling", which was organized by the executive directive of U.S. President Barack Obama, and the interim report of Joint Investigation team of U.S. Coast Guard and BOEMRE of "Report of Investigation into the Circumstances Surrounding the Explosion, Fire, Sinking and Loss of Eleven Members Aboard the Mobile Offshore Drilling Unit Deepwater Horizon". The review is focused on the response to the oil spill. And the paper suggests how to improve national marine pollution response policy. In the paper, the Korean governments is suggested to reinforce the capability for instructing and supervising the responsible party's source control measures, to review how to introduce in-situ burning and vessel of opportunity program into our country, and to continue monitoring on the progress of developments of R&D projects related to oil spill response in the U.S..

• Korean Journal of Optics and Photonics
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• v.34 no.1
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• pp.1-12
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• 2023

In this study, we propose a hybrid phase-control algorithm for multi-channel coherent beam combining (CBC) system by combining the covariant matrix adaption evolution strategy (CMA-ES) and stochastic parallel gradient descent (SPGD) algorithms and analyze its operational performance. The proposed hybrid CMA-ES/SPGD algorithm is a sequential process which initially runs the CMA-ES algorithm until the combined final output intensity reaches a preset interim value, and then switches to running the SPGD algorithm to the end of the whole process. For ideal 7-channel and 19-channel all-fiber-based CBC systems, we have found that the mean convergence time can be reduced by about 10% in comparison with the case when the SPGD algorithm is implemented alone. Furthermore, we analyzed a more realistic situation in which some additional phase noise was introduced in the same CBC system. As a result, it is shown that the proposed algorithm reduces the mean convergence time by about 17% for a 7-channel CBC system and 16-27% for a 19-channel system compared to the existing SPGD alone algorithm. We expect that for implementing a CBC system in a real outdoor environment where phase noise cannot be ignored, the hybrid CMA-ES/SPGD algorithm proposed in this study will be exploited very usefully.

• Geomechanics and Engineering
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• v.32 no.1
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• pp.111-123
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• 2023

The slope of an open cut tunnel is located above the exit of the Leijia tunnel on the Changgan high-speed railway. During the excavation of the open cut tunnel foundation pit, the slope slipped twice, a large landslide of 92500 m³ formed. The landslide body and unstable slope body not only caused the foundation pit of the open cut tunnel to be buried and the anchor piles to be damaged but also directly threatened the operational safety of the later high-speed railway. Therefore, to study the stability change in the slope of the open cut tunnel under heavy rain and excavation conditions, a 3D numerical calculation model of the slope is carried out by Midas GTS software, the deformation mechanism is analyzed, anti-sliding measures are proposed, and the effectiveness of the anti-sliding measures is analyzed according to the field monitoring results. The results show that when rainfall occurs, rainwater collects in the open cut tunnel area, resulting in a transient saturation zone on the slope on the right side of the open cut tunnel, which reduces the shear strength of the slope soil; the excavation at the slope toe reduces the anti-sliding capacity of the slope toe. Under the combined action of excavation and rainfall, when the soil above the top of the anchor pile is excavated, two potential sliding surfaces are bounded by the top of the excavation area, and the shear outlet is located at the top of the anchor pile. After the excavation of the open cut tunnel, the potential sliding surface is mainly concentrated at the lower part of the downhill area, and the shear outlet moves down to the bottom of the open cut tunnel. Based on the deformation characteristics and the failure mechanism of the landslides, comprehensive control measures, including interim emergency mitigation measures and long-term mitigation measures, are proposed. The field monitoring results further verify the accuracy of the anti-sliding mechanism analysis and the effectiveness of anti-sliding measures.

• The Journal of Bigdata
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• v.8 no.1
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• pp.83-97
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• 2023

Project evaluation is the process of evaluating the progress and results of a project. Smart city projects can be divided into system components (infrastructure, services, platforms), or projects can run simultaneously for multiple services. In addition, services are developed and expanded through additional projects. In order to ensure that the smart city, which is composed of various projects, proceeds in accordance with the goals and strategies, periodic project evaluation is required during the project implementation process. The smart city project evaluation system proposed in this paper is designed to provide comprehensive and objective indicators by reflecting various factors that must be considered for projects occurring in all stages of planning, design, construction, and operation of smart cities. The indicators derived from the evaluation system can be used by decision makers to determine the direction of smart city project development. In addition, it is designed so that the performance of the project can be evaluated interim before the end of the project and the feedback obtained from it can be reflected. To introduce the application method of the smart city project evaluation system proposed in this study, the evaluation system developed in this study was applied to the smart city project case of Incheon Free Economic Zone (IFEZ). Based on the evaluation results, items that can maximize the improvement effect of each smart city project item were presented, and the direction of smart city project implementation was suggested. By utilizing a smart city project evaluation system that reflects the characteristics of smart city projects that are composed of multiple projects, comprehensive planning and management of smart city projects will be possible, and this study will serve as a reference for identifying priority improvement factors for projects.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.6
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• pp.856-868
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• 2009

This study was conducted to investigate causes for health problems among college women by analyzing factors related to their dietary habits, physical development, health habits, and blood parameters. The subjects were ages 20 to 24 years, lived in the Seoul area and were randomly selected during March, 2008 to August, 2009. The average height and weight of the overall subjects were $162.02{\pm}4.89\;cm$ and $53.96{\pm}7.00\;kg$, respectively. According to a 3-point assessment scale for the subjects' dietary habits, the average point value was 21.2. The percentage of subjects that ate breakfast daily was only 30.5%, and they omitted regular meals at least once a week. Approximately 83.5% of the subjects reported eating out often or frequently, and preferred Korean foods when they ate out. The subjects had interim meals (snacks) one or two times daily, and 40.4% of them preferred unbalanced meals. As their interim meals, among the 'good' group, ate breaded potatoes (39.3%), carbonated beverages, and ice cream (36.8%), whereas the 'poor' group, drank milk and ate dairy products (38.0%) as well as fast food and fried food (22.8%). Intakes of energy, fat, vitamins $B_2$ and $B_6$, niacin, folic acid, calcium, iron, zinc, and phosphorus were higher in the 'poor' group. The average hemoglobin level ($13.77{\pm}1.00\;g/dL$) among the subjects was within normal range; while 2.7% of subjects had hemoglobin levels under 11.1 g/dL (standard value) and were examined as anemic. The degree of interest in health was 24.5% higher among the subjects who had poor dietary habits. In contrast, among those who had good dietary habits, 49.6% reported they had no interest in regular exercise. The subjects reported that regular meals, nutrient intake, sufficient rest, and sleep as necessary to maintain health. The average amount of sleep obtained by the subjects was 6~8 hours. Among the 'poor' group, 36.2% reported that they exercised regularly, whereas 18.5% of the subjects in the 'good' group reported regular exercise (p<0.05). In conclusion, it appears necessary to provide nutrition education through teaching and to promote nutrition and health to college women so they can control their individual health status and create practicable dietary plans.

• Journal of Global Scholars of Marketing Science
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• v.20 no.1
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• pp.27-34
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• 2010

During the past 10 years, sales of luxury goods increased significantly to more than US$ 130 billion in 2007. In this industry, more than half of the revenue comes from Asia where the average income has risen significantly, and the demand for luxury products is forecast to grow rapidly. Purchasing luxury brands appears to be an intriguing social phenomenon that is profitable for companies in this region. As a newly developed country, Korea is one of the most attractive luxury markets in Asia. Currently, a total of 120 luxury fashion brands have entered the Korean market, primarily in luxury districts in Seoul where the competition is fierce. The purposes of this study are to: (1) identify antecedents of attitude toward luxury brands, (2) examine the effect of attitudes toward luxury brands on customer equity, (3) determine the impact of attitudes toward luxury brands on customer lifetime value, and (4) investigate the influence of customer equity on customer life time value. Previous studies have examined materialism, social need, experiential need, need for uniqueness, conformity, and fashion involvement as antecedents of attitude toward luxury brands. Richins and Dowson (1992) suggested that that materialism influences consumption behavior relative to quantity of goods purchased. Nueno and Quelch (1998) reported that the ownership of luxury brands conveys information related to the owner's social status, communicates an image of success and prestige, and is a determinant of purchase behavior. Experiential need is recognized as an important aspect of consumption, especially for new products developed to meet consumer demand. Since luxury goods, by definition are relatively scarce, ownership of these types of products may fulfill consumers' need for uniqueness. In this study, value equity, relationship equity, and brand equity are examined as drivers of customer equity. The sample (n = 114) was undergraduate and graduate students at two private women's universities in Seoul, Korea. Data collection was conducted using a self-administered questionnaire survey in March, 2009. Data analysis included descriptive statistics, factor analysis, reliability analysis, and regression analysis using SPSS 15.0 software. Data analysis resulted in a number of conclusions. First, experiential need and fashion involvement positively influence participants' attitude toward luxury brands. Second, attitude toward luxury brands positively influences brand equity, followed by value equity and relationship equity. However, there is no significant relationship between attitude toward luxury brand and customer lifetime value. Finally, relationship equity positively influences customer lifetime value. In conclusion, young consumers are an important potential consumer group that tries different brands to discover the ones most suitable for them. Luxury marketers that use effective marketing strategies to attract and engender loyalty among this potentially lucrative consumer group may increase customer equity and lifetime value.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.234-265
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• 2013

Oceanic current maps in the secondary school science and earth science textbooks have played an important role in piquing students's inquisitiveness and interests in the ocean. Such maps can provide students with important opportunities to learn about oceanic currents relevant to abrupt climate change and global energy balance issues. Nevertheless, serious and diverse errors in these secondary school oceanic current maps have been discovered upon comparison with up-to-date scientific knowledge concerning oceanic currents. This study presents the fundamental methods and strategies for constructing such maps error-free, through the unification of the diverse current maps currently in the textbooks. In order to do so, we analyzed the maps found in 27 different textbooks and compared them with other up-to-date maps found in scientific journals, and developed a mapping technique for extracting digitalized quantitative information on warm and cold currents in the East Sea. We devised analysis items for the current visualization in relation to the branching features of the Tsushima Warm Current (TWC) in the Korea Strait. These analysis items include: its nearshore and offshore branches, the northern limit and distance from the coast of the East Korea Warm Current, outflow features of the TWC near the Tsugaru and Soya Straits and their returning currents, and flow patterns of the Liman Cold Current and the North Korea Cold Current. The first draft of the current map was constructed based upon the scientific knowledge and input of oceanographers based on oceanic in-situ measurements, and was corrected with the help of a questionnaire survey to the members of an oceanographic society. In addition, diverse comments have been collected from a special session of the 2013 spring meeting of the Korean Oceanographic Society to assist in the construction of an accurate current map of the East Sea which has been corrected repeatedly through in-depth discussions with oceanographers. Finally, we have obtained constructive comments and evaluations of the interim version of the current map from several well-known ocean current experts and incorporated their input to complete the map's final version. To avoid errors in the production of oceanic current maps in future textbooks, we provide the geolocation information (latitude and longitude) of the currents by digitalizing the map. This study is expected to be the first step towards the completion of an oceanographic current map suitable for secondary school textbooks, and to encourage oceanographers to take more interest in oceanic education.